C/C++ recursion and iteration (loop)

Any problem that can be solved by recursion can be converted into iterative (loop)
. Advantages of recursion : make the program clearer and more concise. Through recursion, more powerful functions can be achieved with less code
. Disadvantages of recursion: when the number of recursions increases, it will Consumes a lot of time and memory

Recursively calculate the factorial of 0~8

#include <iostream>
using namespace std;
long factorial(int num)
{
    
    
    if(num==0)
        return 1;
    else
        return num*factorial(num-1);
}
int main()
{
    
    
    int i;
    for(i=0; i<9; i++)
        cout << i << "的阶乘：" << factorial(i) << endl;
    return 0;
}

Calculate the factorial of 0~8 in a loop

#include <iostream>
using namespace std;
long factorial(int num)
{
    
    
    int i, result=1;
    if(num==0)
        return 1;
    for(i=num; i>=1; i--)
        result*=i;
    return result;
}
int main()
{
    
    
    int i;
    for(i=0; i<9; i++)
        cout << i << "的阶乘：" << factorial(i) << endl;
    return 0;
}